Pocket-rule



(No Model.)

lR. R. WADDE-LL.

POCKET RULE.

Patented Feb. 22, 1887.

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ROBERT It. WADDELL, OF HILLSBOROUGH, OHIO.

POCKET-RULE.

SPECIFICATION forming part of Letters Patent No. 358,308, dated February 22, 1887.

Application filed August 23, 1886. Serial No. 211,632. (No model.)

To ctZZ whom it may concern:

Be it known that I, ROBERT It. WADDELL, of Hillsborough, county of Highland, State of Ohio, have invented a new and useful Improvebe readily found without employing mathematical calculation for geometrical drawing, thus greatly facilitating and simplifying the operation.

Tothe above purpose my invention consists in a graduated arm pivoted upon the measuring-rule, and adapted to be extended therefrom so -as to conform to a circular line of movement described by said rule, as hereinafter described and claimed.

My invention further consists in certain peculiar and novelv features of construction and arrangement, as hereinafter described and claimed.

In order that my invention may be fully understood, I will proceed to describe it with reference to the accompanying drawings, in which- Figure 1 is a plan view of a measuring-rule in folded condition with my improved attachment applied thereto. Fig. 2 is asimilar view showing the attachment extended. Fig. 3 is a plan view of the rule and its attachment, both extended as in use.l

In the said drawings, a designates a pocketrule having the middle pivot-joint, av, and the two hinge-joints a2 a in the usual manner. Upon one of the outer arms, at, of the said rule is formed a recess, c5, which extends parallel with one edge of said arm, and has at one end an enlargement, er.

Within the recess a5 is placed the attachment B, which is a straight arm corresponding in form and dimensions with the recess a5,

and having at one end an enlargement, Z1, fitting the enlargement a of recess e5 and pivoted therein, as shown at b. Upon one of its sides this arm B is graduated to fractions of inches, as at b2, so that when the arm is not extended its outer graduated side shall eon- L form to the graduations upon the rule. Upon the opposite or under side the said arm is graduated to degrees of a circle, whose center is the pivot a', and whose radius is a line drawn from the pivotjoint a to the pivot b of the arm B.

In order to find the degree of an angle, the rule a is extended, as shown in Fig.3, and the arm B is extended out of its recess a5, so as to lie at right angles to the contiguous edge of the rule. The pivot 0f joint- (M is placed upon the vertex of the angie, and the arm al of the rule is held firmly in stationary conditionwliile the arm at is moved in the arc of a circle equal in length to the arm B. The lower edge ofthe rule will now be on an angle of fifteen degrees from the point started from. This circular movement being continued, any desired number of degrees oi' a circle may be readily reached and quickly indicated upon the surface being measured. A single degree is indicated by dotting a line at the one-degree 'mark of arm B, and continuingthe movement of arm et as before till the point is on a line with the dot, when the angle will measure exactly one degree. i

The attachment may be of metal or other suitable material, and does not interfere with the ordinary uses of the rule, while greatly grecs of a circle, and pivoted upon one arm of the rule, substantially as described.

2. The combination, with a measuring-rule having a recess, c?, with an enlarged portion, a, said recess being formed in the edge of one arm of the rule, of an arm, B, graduated upon one side to fractions of inches and upon the i opposite side to fractions of degrees, and pivgraduated sides b2 b3, substantially :is and for oted in said recess, one end of said arm B the purpose speeifiec. 1o being enlarged to fit the enlarged portion of In testimony whereof I have hereunto set the recess, as set forth. my hund this 30th day of June, A. D. 1886.

5 3. The rule a, having joints a aia, and arms ROBERT R. VVADDELL.

a* a7, and provided with the recess a5, with its Witnesses: enlargement a, in combination with the arm HARRY RICHARDS,

B, having enlargement b and pivot b', and A. N. SMITH. 

